Packages

trait Exprs extends AnyRef

EXPERIMENTAL

A trait that defines strongly-typed tree wrappers and operations on them for use in Scala Reflection.

Expr wraps an abstract syntax tree (scala.reflect.api.Trees#Tree) and tags it with its type (scala.reflect.api.Types#Type).

Usually Exprs are created via scala.reflect.api.Universe#reify, in which case a compiler produces a scala.reflect.api.TreeCreator for the provided expression and also creates a complementary scala.reflect.api.TypeTags#WeakTypeTag that corresponds to the type of that expression.

Exprs can also be created manually via the Expr companion object, but then the burden of providing a TreeCreator lies on the programmer. Compile-time reflection via macros, as described in scala.reflect.macros.Aliases, provides an easier way to instantiate exprs manually. Manual creation, however, is very rarely needed when working with runtime reflection.

Expr can be migrated from one mirror to another by using the in method. Migration means that all symbolic references to classes/objects/packages in the expression are re-resolved within the new mirror (typically using that mirror's classloader). The default universe of an Expr is typically scala.reflect.runtime#universe, the default mirror is typically scala.reflect.runtime#currentMirror.

Self Type
Universe
Source
Exprs.scala
Linear Supertypes
AnyRef, Any
Known Subclasses
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Inherited
  1. Exprs
  2. AnyRef
  3. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. All

Type Members

  1. trait Expr[+T] extends Equals with Serializable

    Expr wraps an abstract syntax tree and tags it with its type.

    Expr wraps an abstract syntax tree and tags it with its type. The main source of information about exprs is the scala.reflect.api.Exprs page.

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from Exprs to any2stringadd[Exprs] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (Exprs, B)
    Implicit
    This member is added by an implicit conversion from Exprs to ArrowAssoc[Exprs] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  6. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  7. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  8. def ensuring(cond: (Exprs) ⇒ Boolean, msg: ⇒ Any): Exprs
    Implicit
    This member is added by an implicit conversion from Exprs to Ensuring[Exprs] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  9. def ensuring(cond: (Exprs) ⇒ Boolean): Exprs
    Implicit
    This member is added by an implicit conversion from Exprs to Ensuring[Exprs] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: Boolean, msg: ⇒ Any): Exprs
    Implicit
    This member is added by an implicit conversion from Exprs to Ensuring[Exprs] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean): Exprs
    Implicit
    This member is added by an implicit conversion from Exprs to Ensuring[Exprs] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  14. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  15. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  16. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  17. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  18. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  19. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  20. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  21. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  22. def toString(): String
    Definition Classes
    AnyRef → Any
  23. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  24. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  25. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  26. def [B](y: B): (Exprs, B)
    Implicit
    This member is added by an implicit conversion from Exprs to ArrowAssoc[Exprs] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
  27. object Expr extends Serializable

    Constructor/Extractor for Expr.

    Constructor/Extractor for Expr.

    Can be useful, when having a tree and wanting to splice it in reify call, in which case the tree first needs to be wrapped in an expr.

    The main source of information about exprs is the scala.reflect.api.Exprs page.

Deprecated Value Members

  1. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from Exprs to StringFormat[Exprs] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @deprecated @inline()
    Deprecated

    (Since version 2.12.16) Use formatString.format(value) instead of value.formatted(formatString), or use the f"" string interpolator. In Java 15 and later, formatted resolves to the new method in String which has reversed parameters.

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from Exprs to any2stringadd[Exprs]

Inherited by implicit conversion StringFormat from Exprs to StringFormat[Exprs]

Inherited by implicit conversion Ensuring from Exprs to Ensuring[Exprs]

Inherited by implicit conversion ArrowAssoc from Exprs to ArrowAssoc[Exprs]

Expressions

Ungrouped